Understanding Worker's Approach in a Conventional Assembly Line: An Observational Case Study Using Content and Network Analysis

Consistency in workers' performance is critical to making a system reliable and efficient. Standardizing the work process, often documented as a standard operating procedure, helps maintain consistency. However, standardizing assembly procedures and ensuring consistent performance in conventional assembly lines where workers play a significant role is challenging. This paper presents a methodology to analyze workers' performance in the manufacturing system by examining their work and behavior to create effective standard procedures. First, task analysis was carried out to identify the expected way of performing the assembly task per standard operating procedure. Next, the workers were monitored performing the assembly to conduct content analysis. Lastly, a network analysis was done to study the sequence of tasks followed by the worker. The findings suggest that the workers perceived and executed the assembly differently with some deviations from the standard operating procedure, indicating variability in performance. Furthermore, clusters of tasks frequently carried out during the assembly varied among the observed workers. This methodology can assist manufacturing industries in creating effective standard operating procedures by providing insight into workers' performance. In particular, how workers accomplished the task, the process followed, errors committed, and difficulties encountered during the task. It is also proposed that the methodology will improve plan formation, such as modification of the workstation and assembly process to increase overall system performance.